[February 07, 2014]MINNEAPOLIS (Reuters) —
A southern Minnesota school building was evacuated on
Thursday and 30 elementary students were treated at a local hospital
for possible carbon monoxide poisoning, officials said.

The cause of the incident Thursday morning at the
Springfield Public Schools building has not been determined and
investigators have not picked up carbon monoxide readings in their
search of the facility, Superintendent Keith Kottke said.

"We haven't ruled anything out at this point," Kottke said. "We want
to make sure it isn't an indoor air quality issue."

All but one of the children had been treated and released by late
Thursday afternoon from Mayo Clinic Health System in Springfield and
the remaining child was being evaluated, system spokesman Kevin
Burns said.

More than 600 students from kindergarten through 12th grade attend
school at the building in Springfield, which is about 100 miles
southwest of Minneapolis. It will stay closed Friday while the
investigation continues, Kottke said.

Kottke said fourth- and fifth-graders were practicing in the school's
auditorium Thursday morning for a concert when a handful became ill
followed by others, and first responders found the symptoms might
indicate carbon monoxide exposure.

(Reporting by David Bailey in
Minneapolis and Jon Herskovitz in Austin, Texas; esditing by Leslie
Adler and Ken Wills)